Rookie Robert Blanton slowly working into the mix at safety

Rookie safety Robert Blanton finds himself in an interesting situation as the preseason winds to a close. The fifth-round draft pick out of Notre Dame isn’t only working through a challenging conversion, moving to safety after spending most of his college career at cornerback, he’s also resisting the urge to fight back too fast from the nagging hamstring injury he suffered during the first padded practice of training camp on July 30.

Blanton could see his first preseason game action Friday against the Chargers. A decision on his availability has not yet been made. Yet after missing significant practice time the past month, he must not try too hard to make up for lost time.

“Coming back from a hamstring, it’s one of those injuries where you think you might be ready and then sometimes it will tug a little bit,” head coach Leslie Frazier said. “You have to be careful. So not only mentally does he have to be careful about not trying to get it all back but physically as well. He’s got to kind of move into it a little bit slower than he would probably like to.”

Blanton is also in the early stages of that cornerback-to-safety transition, a move Mistral Raymond pushed through as a rookie in 2011. Raymond needed significant time to get comfortable with his new responsibilities and didn’t become a major part of the rotation until after Thanksgiving when the Vikings’ secondary was floundering.

Said Frazier: “The biggest thing about the transition is you go from being at the corner where you have the sight line that can sometimes help you with certain situations to now being out in space. And [you’re] having to make the calls on defense opposed to someone giving you the calls when you are at the corner. It is a lot more mentally. And there is a lot more required physically as well as far as having a better understanding about angles and broadness of the field.”

On the rise

Another rookie defensive back under the spotlight Friday will be cornerback Josh Robinson, whose development seems to be coming quickly through the preseason. Robinson drew praise once again for his burst and recovery speed during last week’s preseason win over Buffalo. And with Chris Cook sitting this Friday’s game out with a concussion, Robinson should get a more extensive look with the first team defense in nickel packages.

Robinson understands the Vikings view him as a future starter. And the future could come soon if his progress continues.

“I feel like I’ve made strides in cleaning up my technique and paying attention to doing all the little things right,” he said. “I’m really focused on making sure not to make mental errors.”

Etc.

-- Nose tackle Letroy Guion will not play Friday against San Diego after aggravating a right knee injury on Tuesday. Guion suffered a posterior cruciate ligament sprain in the knee during the Vikings’ preseason opener in San Francisco. He did not participate in Wednesday’s practice, watching from the sideline with his right knee wrapped up. Guion did have an MRI on the knee but no structural damage was found.

-- Other notable players who may not play against the Chargers include linebackers Larry Dean (shoulder) and Solomon Elimimian (hamstring) and offensive lineman DeMarcus Love (pectoral). Declared out for Friday are tight end John Carlson, receiver Kamar Jorden and offensive linemen Geoff Schwartz and Bridger Buche.